Polymethine dyes containing a 4-(hydroxymethyl)-or 4-(acetoxymethyl)-delta2-thiazoline or oxazoline nucleus, and preparation thereof



United States Patent This invention relates to polymethine dyescontaining a 4-(hydroxymethyl)- or a 4-(acetoxymethyl)-A -thiazoline or-oxazoline nucleus, and to methods for preparing them.

Some cyanine dyes, derived from the unsubstituted A oxazoline nucleus,are known.

We have now found an entirely new class of polymethine dyes which areuseful as sensitizers for photographic emulsions; It is, accordingly, anobject of our invention to provide a new class of polymethine dyes. Afurther object is to provide methods for preparing these new dyes. Stillanother object is to provide photographic silver halide emulsionssensitized with these new dyes. Other objects will become apparent froma consideration of the following description and examples.

According to our invention we provide new polymethine dyes containing aA -thiazoline or a A -oxazoline nucleus contaning a 4-(acetoxymethyl)-or a 4- (hydroxymethyl)-substituent.

More particularly, we provide new polymethine dyes selected from thegroup consisting of- (1) Cyanine dyes represented by the followinggeneral formula "ice 2 methylbenzothiazole,'etc.), those of thenaphthothiazole series (e.g. alpha-naphthothiazole,beta-naphthothiazole, 5-methoxy-beta-naphthothiazole,S-ethoxy-beta-naphthothiazole, 8-methoxy-alpha-naphthothiazole,7-methoxyalpha naphthothiazole, etc.), those of the thionaphtheno-7',6',4,5-thiazole series (e.g. 4'-rnethoxythionaphtheno-7',6',4,5-thiazole, etc.), those of the oxazole series (e.g.4-methyloxazole, S-methyloxazole, 4-phenyloxazole, 4,5- diphenyloxazole,4-ethyloxazole, 4,5-dimethyloxazole, 5- phenyloxazole, etc.), those ofthe benzoxazole series (e.g. benzoxazole, S-chlorobenzoxazole,5-methylbenzoxazo1e, S-phenylbenzoxazole, 6 -methylbenzoxazole,5,6-dimethyl- .benzoxaz ole, 4,6-dimethylbenzoxazole,S-methoxybenzoxazole, S-ethoxybenzoxazole, S-chlorobenzoxazole, 6-methoxybenzoxazole, S-hydroxybenzoxazole, 6-hydroxybenzoxazole, etc.),those of the naphthoxazole series (e.g. alpha-naphthoxazole,beta-naphthoxazole, etc.), those of the selenazole series (e.g.4-mthylselenazole, 4-phenylselenazole, etc.), those of thebenzoselenazole series (e.g. benzoselenazole, 5 -chlorobenzoselenazole,5- methoxyvbenzoselenazole, 5-hydroxybenzoselenazole,tetrahydrobenzoselenazole, etc.), those of the naphthoselenazole series(e.g. alpha-naphthoselenazole, beta-naphthoselenazole, etc.), those ofthe thiazoline series (e.g. thiazoline, 4-methylthiazoline,4-hydroxymethyl-4methyl-thiazoline, 4,4 bis hydroxymethyl thiazoline,4-acetoxymethyl-4- methyl-thiazoline, 4,4-bis-acetoxymethyl-thiazoline,etc.), those of the oxazoline series (e.g. oxazoline,4-hydroxymethyl-4-methyl-oxazoline, 4,4-bis-hydroxymethyl-oxazoline,4-acetoXy-methyl-4-methyleoxazoline, 4,4 bis acetoxymethyl-oxazoline,etc.), those of the Z-quinolin'e series (e.g. quinoline,3-methylquinoline, S-methylquinoline, 7- methylquinoline,8-methylquinoline, 6-chloroquinoline, 8-

wherein R and R each represents an allyl group such Z represents thenon-metallic atoms necessary tof'comt plete -a heterocyclic nucleuscontaining from 5 to 6 atoms in the heterocyclic ring such as thoseselected from the group consisting of those of the thiazole series (e.g.

chloi'oquinoline, 6-methoxyquinoline, 6-ethoxyquinoline,

6-hydroxyquinoline, 8-hydroxyquinoline, etc.), those of ,the 4-quinolineseries (e.g. quinoline, 6-methoxyqui-noline,

7 methylquin oline, S-mthylquinoline, etc.), those of the'l-isoquinoline series (e.g. isoquinoline, 3,4-dihydroiso- -quinoline,etc.), those of the 3-isoquinoline series (e.g.

series (e.g. 3,3-dimethylindolenine, 3,3,5-trimethylindothiazole,4-methylthiazole, 4-phenylthiazole, S-methylthiazole, S-phenylthiazole,4,5-dimethylthiazole, 4,5-diphenylthiazole, 4-(2-thienyl) thiazole,etc.), those of the benzothiazole series (e.g. benzothiazole,4-chloro-benzothiazole, S-chlorobenzothiazole, 6-chlorobenzothiazo1e, 7-chlorobenzothiazole, 4-methy1benzothiazole, S-methylbenzothiazole,6-methylbenzothiazole, S-bromobenzothiazole, 6 bromobenzothiazole, 4phenylbenzothiazole, 5-

phenylbenzothiazole, 4-methoxybenzothiazole, 5-methoxybenzothiazole,6-methoxybenzothiazole, 5-iodobenzothiazole, 6-iodobenzothiazole,4-ethoxybenzothiazole, 'S-ethoxybenzothiazole, tetrahydrobenzothiazole,5,6-dimethoxyzenzothiazole, 5,6-dioxyrnethylenebenzothiazole, 5-

hydroxybenzothiazole, 6-hydroxybenzothiazole, 5,6-diisoquinoline, etc.),those of the 3,3-dialkylindolenine lenine, 3,3,7-trimethy1indolenine,etc.), those of the pyridine series (e.g. pyridine, S-methylpyridine,etc.), those of the benzimidazole series (e.g. 1,3-diethylbenzimidazole, 1-ethyl-3-phenylbenzirnidazole, l ethyl-S-hy-.droxyethyl-5,6-dichlorobenzimidazole,1-ethyl-3-acetoxyethyl-5,6-dichlorobenzimidazole,1,3-dethyl-5-chlorobenzimidazole, 1,3diethyl-6-chlorobenzimiclazole,'etc.), and

X represents-an acid radical such as chloride, bromide,

iodide, perchlorate, benzenesulphonate, p-tolusulphonate,methylsulphate, ethylsulphate, etc.

' (2)"Styfyl1dyes represented by the following'general formula YCH2 R: pCH2--OB Rs i V I CHz-A I wherein R, A, B and X have the values as setforth above and R and R each represents an alkyl group such as methyland ethyl' (3) Merocyanine dyes represented by the following generalformula III wherein R, A, B and Y have the same value as set forthabove, m represents a positive integer from 1 to 3, L and L eachrepresents a methine group such as the methine group defined by L and Labove and Q represents the non-metallic atoms necessary to complete aheterocyclic nucleus containing five atoms in the heterocyelic ring,three of said atoms being carbon atoms, at least one of both atoms whichare not carbon atoms being a nitrogen atom, the other being selectedfrom the group consisting of oxygen, sulphur and nitrogen atoms, e.g. a2-thio-2,4-thiazolidine-dione nucleus such as a S-ethylrhodaine nucleus,a 3-allylrhodanine nucleus, etc., a 2-thio-2,5-thiazolidine dionenucleus, a 2-thio-2,4- oxazoledione nucleus, a pyrazolone nucleus, a2-thiohydantoine nucleus such as a 1-phenyl-3-n-hexyl-2-thiohydantoinenucleus, a l-ethyl-3-methyl-2-thiohydantoine nucleus etc., aZ-ethylthio-S-thiazolone nucleus, etc.

(4) Rhodacyanine dyes represented by the following general formulawherein B, A, R, Y and X have the values as set forth above.

The heterocyclic cyclamrnonium quarternary salts represented by FormulaVI can easily be prepared by quaternization of the corresponding2-methyl-4-(acetoxymethyl)- or 2-methyl-4-(hydroxymethyl)-A -thiazolinesor -oxazolines represented by the following general formula V V whereinR, R L L L L 11, m, Z, B, A, Y and X have the values as set forth above,p represents a positive integer from 1 to 2, R, represents analkyl-group such as methyl, ethyl, propyl allyl etc. (e.g. analkyl-group of the formula C H wherein q represents a positive integerfrom 1 to 4), and Q and Q represents together the non-metallic atomsnecessary to complete a heterocyclic nucleus containing five atoms inthe ring, at least one atom being a carbon atom to which is attached anoxygen atom by a double bound such as a 4-thiazolidone nucleus, aS-thiazolidone nucleus,,a hydantoine nucleus, etc.

(5) Rhodacyanine dyes represented by the following general formula R Qand Q have the values as set forth above.

According to the process of our invention We prepare the polymethinedyes represented by the Formulae I, II, III, IV and V starting from thecyclammonium quaternary salts represented by the following generalformula of the B-polyhydroxy-t-butylamines of the following formulaHO-HzC CHzOH VIII 7 wherein A represents an hydroxylgroup or hydrogen,and

acetic acid, Whilst simultaneously removing the released water (see J.Nys and J. Libeer, Bull. Soc. Chim. Belg, 65 (1956), 377-402). The2-methyl-4-(acetoxymethyl)- A -oxazolines (Formula VII, Y=O, B=COCH andA=OCOCH or H) can advantageously be prepared by refluxing an intimatemixture of the B-polyhydroxy-tin the 4.-position, generally reactreluctantly wth suitable intermediates to give the correspondingpolyme'thin'e'dyes, the 4-(hydroxymethyl) or 4-(acetoxymethyl)substituted 2methyl-A -thiaz0lines and '-oxazolines are, afterquaternization, easily condensed in the usual manner to the desiredpolymethine dyes, e.g. symmetrical trimethinecyanine dyes when thecondensation occurs in the presence of ethyl-ortho-formate. The enhancednucleophilic reactivity of the 2-methyl carbon-atom is maintained whenthe 4-substituted oxazolineand thiazoline quaternary cyclammonium saltsare condensed with suitable electrophilic intermeidates in view of thepreparation of asymmetrical trimethineand pentamethine cyanine dyes,merocyanine dyes, styryl dyes and rhodacyanine dyes.

New asymmetric cyanine dyes can be prepared according to the process ofour invention, by condensing a cyclammonium quaternary salt selectedfrom those repre sented by Formula VI, with a cyclammonium quaternarysalt represented by the following formula wherein R X, Z and n have thevalues as set forth above and D represents an alkylmercapto-, anarylmercaptd, a fi-arylannnovinyh, a S-arylamino-1,3-butadienyl-, aS-alkylmercaptovinylor a fl-arylmercaptovinylgroup. The condensationsare advantageously carried outin the presence of a basic condensingagent e.g. a trialkylamine such as triethylamine, a dialkylaniline, aheterocyclic tertiary amine such as pyridine, N-alkylpiperidine, etc.The condensation can also be carried out in the presence of an inertdiluent such as methanol, ethanol, diethylether, acetone, 1,4-dioxane,etc. 7

New styryl dyes can be prepared according to the process of ourinvention by condensing a cyclammonium quaternary salt selected fromthose represented by Formula V1, with a p-dialkylaminobenzaldehyde,advantage- .ously in the presence of a carboxylic acid anhydrideeg.

acetic anhydride.

New symmetrical carbocyanine dyes can be prepared according to theprocess of our invention by condensing a cyclammonium quaternary saltselected from those represented by Formula VI with an ortho-carboxylicacid alkylester, such as ethyl-ortho-formate, ethyl-ortho-ace- 'WhereinQ has the value as set forth above a'nd E represents anarylamino-methylene of an -arylaminovinylmethylene group, advantageouslyin the presence of a e basic condensing agent as set forth above.

According to a further feature of our invention,'the cyclammoniumquaternary salts selected from those represented by Formula VI can becondensed with a compound represented by the following formula wherein rrepresents an integer from 1 to 3 and Ar an aryl group. Thearylaminovinyl intermediates, or vinylene homologous thereof, obtainedcan be transformed in the corresponding acetarylido derivatives byboiling with "at 100 C. for hours.

acetic anhydride giving intermediate compounds represented'by thefollowing formula I wherein B, A, Y, X, R, r and Ar have the values asset forth above. The intermediate compounds thus obtained can becondensed with cyclammonium quarternary salts containing a methyl groupin ocor 'y-position, such as those represented by the following generalformula.

XII

wherein R, X, Z and n have the values as set forth above,

to unsymmetrical cyanine dyes. The condensations are advantageouslycarried out in the presence of a' basic condensing agent as set forthabove.

The intermediate compounds can also be condensed with cyclicketomethylene compounds represented by the following formula //Q\\O=C-C=H2 V e V or with compounds represented by the following formula rV O=b=CH-CH: wherein Q has the value asset forth above, to diand Therhodacyanin'es according to our invention can be prepared in the usualway from the merocyanines of Formula III or from the cyclammoniumquaternary salts represented by Formula VI.

Preparation of the 2,4-dimethyl-4-hydroxymethyloxazoline-ethiodide(Formula VI, Y=O, B=H and A=H) 2,4-dimethyl-4-hydroxymethyl-oxazoline(2.60 g.) and ethiodide (3.40 g.) were heated at C. in a sealed tube for16 hours. After washing with ether and acetone, it

had M.P. 167-469 c. v e 7 Preparation of the'2-methyl-4,4-bis-(hydroxymethyD-oxazoline-ethiodide (Formula VI, Y=O,B=H and A=OH) Z-methyl 4,4 bis-(hydroXymethyD-oxazoline (10 g.) andethyliodide (6 cm. were heated in a closed vessel The residual oil isdissolved in boiling acetone and the pure ethiodide crystallized oncooling this solution.

After recrystallization from acetone it had 102- Preparation ofthe2,4-dimethyl-4-aceto5cymethyl-oxazoline-ethiodide (Formula VI, Y=O,B=COCH A=H) 2,4 dimethyl 4 acetoxymethyl-oxazoline (3.4 g.) andethiodide 3.4 g.) were heated in a closed vessel at 100 C. for 16 hours.The reaction mixture was washed with acetone-ether, and the residual oilrecrystallized from ethanol, to give the pure ethiodide, M.P. 104105 C.

2,4-dimethy1- 4 acetoxymethyl-thiazoline (9.4 g.) and ethyliodide (8.6g.) were heated in a closed vessel at 100 C. for 50 hours. The yellowoil was washed'with ether,

and recrystallized from anhydrous ethanol, yielding the pure ethiodide,M.P. 139 0. a

'further distilled in vacuo.

Preparation of the 2-methyl-4,4-bis-(acetoxymethyl)-thi-'azoline-ethiodide (Formula VI, Y=S, B=COCH A=OCOCH Preparation of the2,4-dimethyl-4-acetoxymethyl-thiazoline and the2-methyl-4,4-bis-(acetoxymethyl) -thiazoline (Formula VII, Y=S) Cf. ourcopending application filed on even date herewith, 4-hydroxymethyland4-acetoxymethyl-2-methyl- A -thiazolines and preparation thereof.

"Preparation of the 2-methyl-4,4-bis-(hydroxymethyl)- oxaz'oline(Formula VII, Y=O, B=H, A=OH) 5,6,5-Trihydroxy-t-butylamine (FormulaVIII, A: OH) (24 g.) was dissolved in acetic acid (18 cm?) and themixture heated under reflux in a fractionating column assembly providedwith an adequate still head. The water, liberated during the reaction,was continuously removed. After the theoretical amount of water (7.2cm?) had distilled, the residual light-yellow liquid was the range150-165 C. under a vacuum of 5 mm. Hg was dissolved in boiling dioxane.Diethyl ether was cautiously added to the hot solution until a slightturbidity was produced. After cooling, the precipitated crystallinesolid was removed by filtration.

Recrystallization from chloroform-ether and finally from ethyl-acetategave the pure oxazoline, M.P. 95-

Preparation of the 2,4-dimethyl-4-hyaroxymethyloxazoline (Formula VII,Y=O, B=H, A=H) This was prepared in the same manner as the corresponding 4,4'-bis-(hydroxymethyl)-derivative, from 5,5-dihydroxy-t-butylamine (Formula VIII, A=H, 21 g.) and acetic acid (13cmfi). The crude 2,4-dimethyl-4- hydroxymethyl-oxazoline, which remainedin the reaction flask as a syrupy liquid after the liberated water andthe excess acetic acid were removed under reduced pressure,

was purified by distillation at atmospheric pressure, B.P. 207209 C. Itcrystallized on standing overnight at C., M.P.30-31 C.

Preparation of the 2,4-dimethyl-4-acet0xymethyl-oxazoline (Formula VII,Y=O, B=COCH A=H) ;8,B-bis-(Hydroxy)-t-butylamine (10.5 g.) and aceticanhydride (50 cm?) were heated under reflux for 1 hour. After removal ofthe liberated acetic acid and of the excess acetic anhydride, thereaction mixture was further distilled at atmospheric pressure and the2,4-dimethy1-4-acetoxymethyloxazoline, B.P. 208-210 C., was

. obtained in a yield of 70%.

was precipitated by addition of ether. A syrupy oil was obtained, whichwas used without further purification.

The fraction, distilling over- Preparation of the2-(2'-acetanilidovinyl)-4-methyl-4- acetoxymethyl-oxazoline-ethiodide(Formula XI, Y: O, A=H, B=COCH r=2) This intermediate was obtainedsimilarly from 2,4-dimethyl-4-acetoxymethyl-oxazoline ethiodide (5 g.),diphenylformamidine (6 g.) and acetic anhydride (8 cm. The resultingviscous oil was used without further purification in the preparation ofthe dyes.

Preparation of the 2-(2'-acetanilidovinyl)-4-methyl4-acetoxymethylathiazoline ethiodide (Formula XI, Y: S, A=H, B=COCH r=2)This intermediate was prepared in the usual way, from2,4-dimethyl-4-acetoxymethyl-thiazoline ethiodide (3.4 g.) anddiphenylformamidine (2.9 g.), which were thoroughly mixed and heated atfor /2 hour. After cool ing, the reaction mixture was washed with ether,whereby the crude anilinovinyl derivative was obtained as an oil. Thelatter crude reaction product (3.2 g.) and acetic anhydride (5 cm?) wereheated under reflux for 15 minutes. Ether was then added to the chilledreaction mixture, whereby the acetanilidovinyl derivative separated as asolid. The precipitate was collected and washed several times withether-acetone. It had M.P. 208-211" C.

Preparation of the2-(2'-acetanilidovinyl)4,4-bis-acetoxymethyl)-thiazoline ethiodide(Formula XI, Y=S, A=OCOCH B=COCH r=2) .This intermediate was obtainedfrom 2-methyl-4,4- bis-(acetoxymethyl)-th iazoline ethiodide (2 g.) anddiphenylformamidine (1.25 g.) which were intimately 'mixed, and heatedtogether at for 20 minutes. The

yellow oil, obtained by washing the cooled reaction mixture with ether,was heated in boiling in acetic anhydride (3 cm. for 5 minutes. Thedesired acetanilidovinyl derivative separated as an oil on addition ofether. It was used without further purification.

Preparation of the Z-acetanilido-tetramethine-4,4-bis-(acetoxymethyl)-oxazoline ethiodide (Formula XI, Y=O, A=OCOCH B=COCHr=3) EXAMPLE 1 [2 {3 ethyl naphtha (1'22 4:5) thiaz0le}l- [2 {3 ethyl4,4 bis (acetoxy methyl) oxaz0line}1-trimethinecyanine iodide (dye No.2, Table I) 2 (2 acetanilidovinyl) 4,4 bis (acetoxymethyl)- oxazolineethiodide (2.0 g.) and Z-methyl-naphtho- (l':2'-4:5)-thiaz0le ethiodide(1.5 g.) were dissolved in ethanol (15 cmfi). The solution was cooled inice. Tricthylamine (0.5 cm?) was then added, and the reaction mixturewas kept at 0 for 15 minutes. Ether was added to the solution, wherebythe dye precipitated. It recrystallized from ethanol, M.P. 137-139 C.(Found: N, 4.25%; C H O N SI requires N:4.50%); 7t max.=479 m EXAMPLE 2[2-{3-ethyl-naphth0-(1 2' 4:5) -thiaz0le}] 4 [2-(3-ethyl-4-methyl-4-a'cetoxymethyl-oxazoline) l-trimethinecyanine iodide (dye N0.3, Table I) A mixture of2-(2-acetanilidovinyl)-4-methyl-4-acetoxymethyl-oxazoline ethiodide (2.3g.), Z-methyl-naphtho-(1:2-4:5)-thiazole ethyl-ethosulphate and pyridine(20 cmfi) were boiled under reflux for 10 minutes. The dye precipitatedwhen ether Was added to the cooled reaction mixture. Afterrecrystallization from methanol,

,954 3 9 -9 10 it had M.P. 179181 C. (Found: N, V 4.80%; g.) andtriethylamine (0.7 cm?) in ethanol (15 cmd"). C2 H O N SI requires N,4.96%); A max.=497 ml. After recrystallization from ethanol, the dye hadM.P. EXAMPLE 3 I 169170 C." (Found: N, 5.82%; C H O N .ClO re-[2-(3-ethylbenzothiazole) ]-[2-{3-ethyl-4,4 bis -(acetxymethyl)-oxaz0line} -trimethinecyanine perchlorate (dye No. 5, Table I) l 2 (2'-acetanilidovinyl)- 4,4 bis -(acetoxymethyl)'- oxazoline ethiodide (2.6g.) and 2-methylbenzothiazole ethiodide (1.5 g.) were dissolved inethanol (15 cm.?).

The solution was cooled in ice, and triethylamine (0.7 cmfi) was slowlyadded. The mixture was kept at 0 C. for 15 minutes. Ether was then addeduntil the dye precipitated. The dye was then redissolved in ethanol andtransformed into the corresponding perchlorate with an aqueous solution(10%) of sodium perchlorate. After recrystallization from ethanol, ithad M.P. 161- 162 C. (Found: N, 5.13%; C H O N S.ClO requires N, 5.14%);A max.=478 m EXAMPLE 4 [2-(3-ethylbenzothiazole)1-[2-(3-ethyl-4methyl-4-acet0xymethyl-oxazoline)l-trimethinecyanine perchlorate (dyeN0. 6, Table I) This dye was obtained similarly from2-(2'-acetanilidovinyl)-4-methyl-4-acetoxymethyl-oxazoline ethiodide(2.36 g.), Z-methylbenzothiazole ethiodide (1.5 g.) and triethylamine(0.7 cm. The dye recrystallized from ,ethanol' to give the pure cyanineperchlorate, M.P. '197- 199 C. (Found: N, 5.73%; C21H27O3N2S.C].O4requires 5.75%); A max.=477 ma.

EXAMPLE 5 [2-(3-ethylbenzoselenazole)J-[Z-(S-ethyl 4 methyl-4-acet0xymethyl-0xaz0line)l-trimethinecyanine perchlorate (dye No. 8,Table I) was obtained similarly from 2 -(2'-acetanilidovinyl)-4-methyl-4-acetoxymethyl oxazoline ethiodide (2.36 g.),2-methylbenzoselenazole ethiodide (1.8 g.) and triethylamine (0.7 cmfi).

' After-recrystallization from ethanol, the cyanine perchlorate had M.P.194-495 C. (Found: N, 5.25%;

C H O N SeClO requires N, 5.24%); A max.=482 m EXAMPLE 6 [2-(3-ethylbenz0selertaz0le) [2-{3-ethyl-4,4-bis-(acetoxymethyl)0xaz0line}]-trimethinecyanine perchlorate (dye N0. 9, Table I) wasobtained similarly from' 2- (2'-acetanilidovinyl) -4,4-bisacetoxymethyl-oxazoline ethiodide (2.65 g.), Z-methylbenzoselenazole ethiodide (1.5g.) and triethylamine (0.7 cm?) in ethanol (15 cm.*). Afterrecrystallization from methanol, it had M.P. 154l55 C. (Found: N, 4.64%;

[2-(1 -ethylquin0line) [2-(3-ethyl-4-methyl-4-acetoxymethyl-oxazoline)l-trimethinecyanineperchlorate (dye No. 13, Table I) was similarly obtained from 2-(2-acetanilidovinyl) 4 methyl-4-acetoxymethyl-oxazo1ine ethiodide (2.36g.), Z-methylquinoline ethobromide (1.3:

4.93% A max.=505 ma.

quires N, 5.82% A max.=507 m EXAMPLE 9 [2-(1 ethylquin0line)]-[2-{3-ethyl-4,4-bis -(acet0xymethyl)-obcaz0lihe}]-trimethinecyaninei0dide'(dye No. 14,

Table I) A mixture of-2-(2'-acetanilidovinyl)-4,4-bis-(acetoxymethyl)-oxazoline ethiodide(2.65 g.), 2-methylquinoline ethiodide (1.3' g. triethylamine (0.7 cmfi)and ethanol (15 cm?) was kept at 0 C. for 15 minutes with stirring.Ether was then added, whereby the dye precipitated. Afterrecrystallization from ethanol, it had M.P. 117- 118. (Found: N, 4.82%;C H O N I requires N,

EXAMPLE 10 [2 -(3-p-carb0xybenzyl-5,6-dimethylb enzoth iazole)l [2- (3ethyl 4 methyl-4-acet0xymethyl-thiazoline) l-trimethinecyanineperchlorate (dye N0. 16, Table II) 2 (2'1 acetanilidovinyD- 4methyl-4-acetoxymethylthiazolineethiodide (4.8 g.2,5,6-trimethylbenzothiazolep-carboxy-benzylbromide (4.0 g.), ethanolcm. and triethylamine (1.4 cmfi) were kept at 0 C. for 3 hours. Thedyestulf was then precipitated with an aqueous solution (10%) of sodiumperchlorate. It recrystallized from ethanol-water to give the pure dye,M.P. 234 C. (Found: N, C29H3304N2S2-Cl04 requires N, 4.39%); A max.=514mp.

j p EXAMPLE '11 [2 -(3 ethyl d-methylbenzoseler zazole)]-[2-(3-ethyl-4-"lllhjll 4 acetoxy methyl thiaz0line)] trimethinecyanine" perchlorate(dye No. 18, Table 11) i 2-(2'-acetanilidovinyl) 4 -methyl 4acetoxymethylthiazoline ethiodide (7.2 g.), 2,6-dimethyl-benzoselenazoleethiodide, ethanol (100 ear and triethylamine (1.4 cmfi) were kept at 10C. for 5 minutes. The crystals, collected after precipitation with anaqueous solution (10%) of NaClO were recrystallized from ethanol, M.P.180-182" C. (Found: N, 4.90%;

CggHggOzNgSSQClO}; requires N, 4.96% A max.=514 m EXAMPLE 12 g V[2-(3-ethylbenz0selenazole)]P[2-{3-ethyl 4,4bis-(acetoxymethyl)-thiaz0line}J-trimethinecyanine perchlorate (dye N0.20, Table II) 2-(2"-acetanilidovinyl)-4,4-bis (acetoxymethyl) thiazolineethiodide (1.3 g.), 2-methyl-benzoselenazole ethobromide (0.75 g.),ethanol (10 cmfi) and triethylamine (0.4 crnfi) were mixed atroom-temperature, and cooled with ice. The mixture was kept at 0 C. for1 hour with stirring. On adding an aqueous solution 10%) of sodiumperchlorate, the dye precipitated. After repeated recrystallization fromalcohol, it had M.P. 189-191 C. (Foundi N, 4.59%; C H gO N SS6.ClOrequires N, 4.61%); A max.=515 m EXAMPLE 13 bis-(acetoxy-methyl)thiazoline}] trimethinecyanine iodide (dye No. 22, Table II)2-(2-anilinovinyl)-benzoxazole-p-carboxy benzylbromide (2.2 g.) and2-methyl-4,4-bis-(acetoxymethyl)-thiazoline ethiodide (2 g.), weredissolved in pyridine (10 cm. The mixture was then heated under refluxfor 10 minutes. After chilling, ether was added in excess, whereby thedye precipitated. It was redissolved in ethanol and reprecipitated withan aqueous solution (10% of potassium iodide. h After recrystallizationfrom ethanol-ether times) it had M.P. 188-190 (Found:Z-methylmercapto-benzothiazole-methyl methosulfate N, 4.10%;C29H31O7N2SI requires N, 4.13%); A max.=. (2.50 g.) and2,4-dimethyl-4-aceoxymethyl-oxazoline 475mg. ethiodide (2.50 g.) weredissolved in ethanol cm. EXAMPLE l4 and triethylamine (1 cm. was added.The mixture was 5 heated under reflux for minutes, and cooled in ice,'gig f z fjjgggg xjggfifii whereby the dye crystallized. Afterrecrystallization zoline)]-trimethincyanine perchlorate (dye 24, Table;E; 263-266 (Wlth decomposltwn) H) EXAMPLE 17'phenylmnpfthyhdene)'3'ethy1'4'methy1[2-(1-ethylquinoline)l-l2-(3-ethyl-4-methyl-4-acetoxytoxymethyl-thlazolidine(1.85 g.), l-(fi-hydroxyethyD-Z- math pom olinenmonomethi M tmethyl-5,6-dichlorobenzimidazole ethiodlde (2.3 g.) were y Z ncyanmePerc 5 dissolved in pyridine cm.;,). Piperidine (0.5 cm. O--OH2 was thenadded, and the mixture was heated on a water- CH3 bath at 95 C. for 4hours. The crude dye was precipi- 5 tated by addition of ether. It wasdissolved again in T N ethanol, and reprecipitated therefrom with anaqueous J I 2 a solution of sodium perchlorate. The pure dye was ob- 2(32H, tained by repeated recrystallisation from ethanol, M.P. 158162 C.(Found: N, 7.00%; C H O N SCl .ClO 20 requires N, 7.02%); max.: 470 mThe 2-(2'-phenyliminoethylidene)3-ethyl-4-rnethyl-4-2-ethylmercapto-quinoline-ethylethosulfate (3.40 g.) and2,4-dimethyl-4-aeetoxymethyl oxazoline ethiodide (3.30 g.) weredissolved in pyridine (20 cm. and triethylamine (1.4 cm?) was added.After shaking the acetoxymethyl-thiazolldine used in the foregoingcondensation was prepared as follows: 2-(2'-acetanilidoXinYl)-4- 'h jf fg .3 3 roonfl g i ii the dye was methyl-4-acetoxymethyl-thiazolineethiodide (3.6 g.) was 25 Preclpl W1 6 transprme mm t e corresPondsuspended in benzene (35 cmfi). A solution of 2.6 g. of mg perchloyateand recrystalhzfid from ethanol (3 tunes) sodium hydroxide in 5 cm. ofwater was then added. water; u had 152 xmaxz 398 After a fegv mirutes,the ginzenekliayer was relmovleddand EXAMPLE 18 evaporate to ryness. eresi ue was re 1sso ve 1n acetone and precipitated as a yellow oil withether. The bls'(acewxymethyl) q phenylimino-ethylidene intermediateappeared'to be soluet y T blswydrwfymethyl) vxazolmefl P ble in boilingligroin but, on cooling, it separated as an methmcymme per ch10 ate oilagain, which could not be brought to crystallisation. H20 0 O-OH2EXAMPLE 15 H:C.OOCH2C\I l I l CHzOH[2-(3-methylbenz0thiazole)1-[2-(3-ethyl 4 methyl-4- (CEDFC C10-hydroxymethyl 0xazoline)] monomethincyamine per- HaC-OOC-H:C III N CHnOHchlorate O 40 Z-acetanilido tetramethin 4,4 bis-(acetoxymethyD- I I CH;oxazoline-ethiodide (1.50 g.) and 2-methyl-4,4-bis-(hy- CCH=C o 01o,-dI'OXymethyl)-oxazoline-ethiodide (0.75 g.) were dis- \CH2OH solved inpyridine (10 cm?) and the resulting mixture 5 l was heated at 9095 C.for 5 hours. The dye was pre- CH; cipitated with ether, redissolved inethanol and trans- Z-methylmercapto benzothiazole methylmethosulfate(1.50 g.) and 2,4-dimethyl-4-hydroxymethyl-oxazoline ethiodide (1.45 g.)were dissolved in ethanol (15 0111. Triethylamine (0.7 cm?) was :addedand the resulting mixture was heated under reflux for 10 minutes. Thedye was transformed into the corresponding perchlorate by adding anaqueous solution (10%) of sodium perchlorate. After washing with waterand recrystallization from formed into the corresponding perchlorate byadding an aqueous solution of sodium perchlorate. Afterrecrystallization from ethanol it had M.P.: 156-160 C. (withdecomposition); A max.: 495 m EXAMPLE 19 Bis-[2-(3-ethyl-4-methyl-4acetoxymethyl oxaz0line)]- trimethincyanine perchlorate ethanol (4times) it had M.P. 235-237" C.; 7\, max. 3582,4-dimethyl-4-acetoxymethyl-oxazoline-ethiodide (5 a. g.) was dissolvedin acetic anhydride (20 cm. Ethyl EXAMPLE 16 orthoformate (5 cm?) wasthen added, and the mixture [2-(3-methylbenzgfhiazgle)]-[2-(3-elhyl 4 hl 4 was heated under reflux for 1 hour. On addition ofacetoxymethyl-oxazoline) ]-m0n0methincyanine-i0dide ether the dye p ipias a thick Yellow O CHZ Qwing to the simultaneous presence of severalhydro- I I CH3 phihc groups in its molecule, it could not been obtained'm a crystalline state, even not as a perchlorate. Its N N purity wasnevertheless sufliciently high to allow the I OHz-OOC- CH; unambiguousdetermination of its absorption maximum,

CH3 (3am Amax; 390 ma.

13 EXAMPLE 20 2-(p-dimethylaminostyryl) -3 ethyl-4-methyl4acet0xymethyloxazolinium perchlorate EXAMPLE 2.1

[2-(3-ethyl 4 methyl-4 ace toxymethylthiazoline) ]-[5- (I-ethyl3-methyl-thiohydantoine)] dimethinemero- 2-(2' acetanilidovinyl)4-methyl 4 acetoxymethylthiazoline ethiodide (4.88 g.) and1-ethyl-3-methyl-thiohydantoine (1.58 g.) were dissolved in ethanol (30cm?) and triethylamine (1.4 cm. was added. The mixture was then heatedunder reflux for minutes. The dye was precipitated with water; afterrecrystallization from ethanol-water (4 times) it had M.P. l45-l47 C.; Xmax.: 460 m/A and 468 m,u..

EXAMPLE 22 [2-(3-ethyl-4-methyl-4 acetoxymethyl thiazoline) 1-[5-(3-ethyl-rhodanine) l-dimethinemerocyanir'ze2,5-dimethyl-4-acetoxymethyl-thiazoline ethiodide (3.43 g.) and3-ethyl-5-acetanilidomethylene-rhodanine (2.00 g.) were dissolved inpyridine (l0 cmfi); triethylamine 1.4 cm?) was then added. The mixturewas then heated under reflux for 30 minutes. The dye was precipitatedwith water as a yellow oil; after recrystallization from ethanol (4times) it had M.P. 126-128 C.; A max.:

14 EXAMPLE 2s [2-(3-ethyl-4-methyl 4-acet0xymethyl-thiaz0line)]-[5-(3-ethyl-rhodanine) ]-tetramethinemerocyanine 2-(2' acetanilidovinyl)-4methyl 4 acetoxymethylthiazoline ethiodide (4.46 g.) and3-ethyl-5-ethylidenerhodanine (1.87 g.) were dissolved in aceticanhydride (20 cm. Triethylamine (1.7 cm?) was added and the mixture wasshaken at room temperature for 15 minutes. The solution was poured intowater, and the syrup that separated was washed several times with water.After recrystallization from ethanol (4 times) the dye was obtained; ithad M.P. 0.; 7x max.: 566 m EXAMPLE 24 [2-(1-methylquinoline)l [5 (3ethyl-rh0danine)-2l- [2-{3-ethyl-4,4 bis (acetoxyn'tethyl)0xaz0line}]-}3- methyl-dimethinerhodacyanine iodide[2-(l-ethylquinoline)l [5 (3 ethylrhodanineH-flmethyldimethinemerocyanine dimethylsulphate (4.68 g.) and 2methyl 4,4 bis(acetoxymethyDoxazoline ethiodide (7.70 g.) were dissolved in pyridine(30 cm. and triethylamine (4.2 cm?) was added. The mixture was heatedunder reflux for 10 minutes. The dye was precipitated with ether as asyrup, which became solid by washing with ether. After recrystallizationfrom ethanol (4 times) it had M.P. -167 C.; 7\ max.: 615

mg. i

We have found that our new polymethine dyes spectrally sensitizephotographic silver halide emulsions when incorporated therein. As maybe seen in Tables I and II, the replacement of one or both of thehydrogen atoms in the 4-position of the thiazolineor oxazoline nucleusby one or two hydroxymethyl or acetoxymethyl groups results in abathochromic shift of the absorption maximum (as well as of thesensitization maximum) of the resulting unsymmertical cyanine dyes.

Further, the cyanine and merocyanine dyes according to our inventionshow a greater solubility in polar solvents than the corresponding dyesderived from A -thiazolines or oxazolines, without hydroxymethylor'acetoxymethyl substituent in the 4-position. Thus, the residual strainsleft in the photographic prints by most of the known sensitizingdyestuffs can easily be avoided or for a great part diminished. The dyescan be incorporated in photographic emulsions by any of the methodscustomarily employed in the art.

17 We claim: A polymethine dye represented by the formula:

a benzoxazole nucleus, a benzoselenazole nucleus, at 6- methylbenzoselenazole nucleus, at naphthothiazole nuwherein A represents amember selected from the group consisting of an acetoxy group, ahydroxyl group, and a hydrogen atom; B represents a member selected fromthe group consisting of an acetyl group and a hydrogen atom; Yrepresents a member selected from the group consisting of an oxygen anda sulphur atom; R and R each represents an alkyl group of the formula CH wherein q represents a positive integer from 1 to 4; n represents apositive integer from 1 to 2; d represents a positive integer from 1 to3; Z represents the non-metallic atom to complete a heterocyclic nucleusselected from the group consisting of a quinoline nucleus, atbenzothiazole nucleus, a 5,6-dimethyl-benzothiazole nucleus,

cleus, a 5,6-dichloro-3-hydroxy-ethyl benzimidazole nucleus, a4-methyl-4-acetoxy methyl-A -oxazolme nucleus, and a 4,4-diacetoxymethyl-A -oxazoline nucleus; and X represents an acid radical of thetype used in cyanine dyes.

References Cited in the file of this patent UNITED STATES PATENTS Nys eta1 Feb. 11, 1958 OTHER REFERENCES Nys et al.: Bull. Soc. Chim. Belg,vol. 65, pp. 377 to 402 (1956).

